fuzz: improve makefile per feedback from some folks at work This is a *ton* better. Once this lands, I can remove a nasty kludge from the oss-fuzz build.sh. Bonus: this fixes the coverage build. Differential Revision: https://phab.mercurial-scm.org/D5458

py3: use bytes stdout in test-check-help.t Setting stdout to binary seemed to have no effect on Windows, as it was appending a literal '\r' to each topic keyword. This also stops prepending 'b' to the topic on all platforms as well.

commandserver: preload repository in master server and reuse its file cache This greatly speeds up repository operation with lots of obsolete markers: $ ls -lh .hg/store/obsstore -rw-r--r-- 1 yuya yuya 21M Dec 2 17:55 .hg/store/obsstore $ time hg log -G -l10 --pager no (hg) 1.79s user 0.13s system 99% cpu 1.919 total (chg uncached) 0.00s user 0.01s system 0% cpu 1.328 total (chg cached) 0.00s user 0.00s system 3% cpu 0.180 total As you can see, the implementation of the preloader function is highly experimental. It works, but I'm yet to be sure how things can be organized. So I don't want to formalize the API at this point.

commandserver: add IPC channel to teach repository path on command finished The idea is to load recently-used repositories first in the master process, and fork(). The forked worker can reuse a warm repository if it's preloaded. There are a couple of ways of in-memory repository caching. They have pros and cons: a. "preload by master" pros: can use a single cache dict, maximizing cache hit rate cons: need to reload a repo in master process (because worker process dies per command) b. "prefork" pros: can cache a repo without reloading (as worker processes persist) cons: lower cache hit rate since each worker has to maintain its own cache c. "shared memory" (or separate key-value store server) pros: no need to reload a repo in master process, ideally cons: need to serialize objects to sharable form Since my primary goal is to get rid of the cost of loading obsstore without massive rewrites, (c) doesn't work. (b) isn't ideal since it would require much more SDRAMs than (a). So I take (a). The idea credits to Jun Wu.